Digital camera with detachable auxiliary memory

ABSTRACT

In a digital camera, the state of copying is monitored and displayed when image data stored in a main memory are copied to an auxiliary memory, and data for preventing illegal copying are added thereto, in order to improve operability and reliability. When a copying mode is designated, the image data stored in the main memory MM upon photographing are transferred and copied to a detachable auxiliary memory MC by way of a bus B. During copying, the number of uncopied image data in the main memory MM and the number of image data which can be copied to the auxiliary memory MC are sequentially displayed in a liquid crystal display section  30 , while each image data is copied with management data indicative of the date and time of copying or the like added thereto. Also, flag data indicating that copying is in progress and that copying has been completed are added thereto. Further, when the auxiliary memory MC is attached to or detached from the camera during copying or photographing, the system is forcibly reset, thereby preventing abnormality from occurring beforehand.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a digital camera which digitallyrecords, into an electronic recording medium such as a semiconductormemory, image data of an object obtained by photographing, for example.

2. Related Background Art

Digital cameras can photograph an object in a simple operation similarto that of conventional silver halide cameras, while having a functionof converting an image of the object captured by a solid-state imagingdevice or the like into digital image data and digitally recording thesedata into a semiconductor memory or the like. Therefore, they have beenattracting much attention as a multimedia-aware photographing deviceapplicable to digital electronic devices such as microcomputer.

The digital cameras have excellent functions in that they can provide avariety of forms of utilization to users. For example, they can providedigital image data to various digital electronic devices such that theyare repeatedly reproduced and displayed, such that the same image dataare copied a number of times, such that the image data are easily editedand processed, and such that unnecessary image are erased while only thenecessary image data are stored and managed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a digital camerawhich has a high degree of operability, facilitates data management, andis highly reliable in terms of functions.

In order to achieve such an object, the present invention is a digitalcamera having a main memory for storing image data obtained byphotographing and a connector means for attaching a detachable auxiliarymemory thereto, wherein further provided is a control means which, upondetection of attachment of the auxiliary memory to the connector means,causes the image data obtained by photographing to be preemptivelystored into the auxiliary memory.

Also, the present invention provides a digital camera having a mainmemory for storing image data obtained by photographing and a connectorfor attaching a detachable auxiliary memory thereto, wherein furtherprovided are a control means which causes the image data in the mainmemory to be transferred and copied to the auxiliary memory according todesignation of a copy mode, and a display means which, as designated bythe control means, sequentially displays the number of uncopied imagedata remaining in the main memory and the number of image data which canbe copied to the auxiliary memory.

Preferably, while causing the image data in the main memory to betransferred and copied to the auxiliary memory, the control means addsmanagement data indicating fact of copying to each image data.

Preferably, the control means adds, to each image data which is to becopied, a flag data indicating that copying of each data is in progress,and adds, upon completion of copying of each image data, a flag dataindicating the completion of copying to each image data which is to becopied.

Preferably, the control means sequentially detects the free capacity ofthe auxiliary memory; upon detection of shortage of the free capacity inthe auxiliary memory before the whole image data in the main memory iscompletely transferred and copied, temporarily stops transferring andcopying operations; and, after detecting that a new auxiliary memory isattached to the connector means, causes the remaining image data to betransferred and copied to the new auxiliary memory.

Preferably, the control means sequentially monitors whether theauxiliary memory is attached to or detached from the connector meansand, upon detection of attachment or detachment of the auxiliary memoryduring transfer of the image data to the main memory or auxiliary memoryin a photographing or copying mode, forcibly initializes the internalcamera system.

The present invention will be more fully understood from the detaileddescription given hereinbelow and the accompanying drawings, which aregiven by way of illustration only and are not to be considered aslimiting the present invention.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will beapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an outer configuration of a digitalcamera;

FIG. 2 is a perspective view further showing an outer configuration ofthe digital camera;

FIG. 3 is a plan view mainly showing a liquid crystal display section ofthe digital camera under magnification;

FIG. 4 is a block diagram showing a configuration of a circuitaccommodated in the digital camera;

FIG. 5 is a flow chart for explaining operations of the digital camera;

FIGS. 6 and 7 are explanatory views for explaining contents displayed onthe liquid crystal display section at the time of photographing by useof a main memory;

FIGS. 8 and 9 are explanatory views for explaining contents displayed onthe liquid crystal display section at the time of photographing by useof an auxiliary memory;

FIG. 10 is a memory map for explaining operations of photographing andcopying modes;

FIG. 11 is an explanatory view for explaining contents displayed on theliquid crystal display section at the time of the copying mode; and

FIG. 12 is a flow chart for explaining the principle and operation of anabnormality monitoring means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, embodiments of the digital camera in accordance withthe present invention will be explained with reference to drawings.Here, FIG. 1 is an outer perspective view showing this digital camerafrom the front face side where an image pickup optical system isprovided; FIG. 2 is an outer perspective view showing this digitalcamera from the back face side where a liquid crystal display section isprovided; and FIG. 3 is an enlarged plan view showing the liquid crystaldisplay section and the like provided at the back face of the digitalcamera.

In FIG. 1, at the front face end of the camera body, disposed are animage pickup optical system 2 which is directed to an object at the timeof photographing; an automatic focus detector 4 which performs distancemeasurement and focus detection; an exposure detecting sensor 6; alight-emitting device 8 which intermittently emits light at the time ofphotographing by use of a timer; a view finder 10; a slide cover 12having a main switch which turns on and off a main power source of thecamera; and a flash 14 disposed at the slide cover 12.

Here, the automatic focus detector 4 adopts so-called active techniquein which, at the time of photographing, its light-emitting device emitslight toward an object, and the light reflected by the object isdetected by a light-receiving device, whereby the distance to the objectand the in-focus state of the image pickup optical system 2 aredetected.

Also, the slide cover 12 is disposed so as to be slidable in X₁-X₂directions in the drawing. As depicted, when it moves in X₂ direction,the above-mentioned main switch turns on the main power source of thecamera; whereas, when it moves in X₁ direction, the above-mentioned mainswitch turns off the main power source of the camera, while the exposuredetecting sensor 6, the light-emitting device 8, and the view finder 10are blocked off.

At the upper end of the camera body, provided are a shutter releasebutton 16 and a zoom button 18. As the shutter release button 16 ispushed down, photographing is effected. The zoom button 18 has atelephoto contact (TSW) and a wide-angle contact (WSW). During a periodin which the zoom button 18 is turned onto the telephoto contact (TSW)side, so-called zoom-in state is continuously set; whereas during aperiod in which the zoom button 18 is turned onto the wide-angle contact(WSW) side, so-called zoom-out state is continuously set.

On one side face of the camera body, provided are a serial port 20 forserially transmitting image data obtained by photographing to anexternal electronic device such as a personal computer; a connector 22for connecting an external power source thereto; and a cover 24 forblocking off the serial port 20 and the connector 22.

In FIG. 2, at the back face of the camera body, provided are a viewfinder window 26 equipped with a light-emitting device 28 whichintermittently emits light at the time of automatic focus detection; aliquid crystal display section 30 for displaying the state of operationof the camera or various operation modes; a mode switch 32 and a selectswitch 34 which are operated in order to designate the operation mode ofthe camera; and an erase switch 36 which is operated in order to erasethe image data already stored in a main memory MM and an auxiliarymemory MC which will be explained later.

In the lower portion of the back face of the camera body, provided are acard slot 38 for detachably inserting a memory card, i.e., the auxiliarymemory MC, thereinto and an eject button 40 which is pushed when thememory card is to be removed from the card slot 38.

The other side end face (right-side end face in FIG. 2) is equipped witha container 42 for accommodating a battery such as a dry cell, and astrap belt 44 which is used when the camera body is held by a hand of anoperator.

In the following, displayed contents of the liquid crystal displaysection 30 will be explained with reference to FIG. 3. In response tooperations of the mode switch 32, select switch 34, and erase switch 36,a plurality of icon marks 46 to 66 are selectively displayed. Thoughthese icon marks are selectively displayed according to operation modes,all the icon marks are shown in FIG. 3 in order to facilitateexplanation.

The icon mark 46 indicates the photographing resolution: “S” indicates astate (referred to as “superfine mode”) where photographing can beeffected with the maximum resolution; “F” indicates a state (referred toas “fine mode”) where photographing can be effected with a predeterminedresolution lower than the maximum resolution; and “N” indicates a state(referred to as “normal mode”) where photographing can be effected witha predetermined resolution lower than the fine-mode resolution.

The icon mark 48 indicates the flash photographing state. The icon mark50 indicates the automatic focus detection mode and the close-upphotographing mode. The icon mark 52 indicates the remaining capacity ofthe battery. The icon mark 54 indicates the manual zoom mode in whichthe zoom button 18 is operated so as to manually set zooming and theautomatic zoom mode in which the camera itself automatically performsoptimal zooming processing while automatically judging in-focusconditions.

The icon mark 56 mainly displays, in terms of segment, the number ofso-called frame picture sheets which can be stored in the main memory MMor auxiliary memory (memory card) MC which will be explained later. Inother words, the remaining storage capacity of the main memory MM orauxiliary memory MC is displayed as the number of sheets of images whichcan be recorded. The icon mark 58 indicates the timer photographingmode.

As a segment display smaller than the icon mark 56, the icon mark 60mainly indicates the number of sheets of so-called frame picturesalready stored in the main memory MM or auxiliary memory MC.

At the time of the copying mode which will be explained later, the iconmark 62 is displayed, indicating that the image data already stored inthe main memory MM is being transferred and copied to the auxiliarymemory MC.

The icon mark 64 indicates the state where the auxiliary memory (memorycard) MC is attached to the card slot 38, whereas it is not displayed inthe state where the auxiliary memory (memory card) MC is detachedtherefrom.

The icon mark 66 indicates a mode in which the image data already storedin the main memory MM or auxiliary memory MC is erased.

As the operator appropriately operates the mode switch 32, select switch34, and erase switch 36, these icon marks 46 to 66 are selectivelydisplayed while being switched over. Further, when one of these iconmarks is designated so as to effect a deterministic operation, theoperation mode of the camera can be selected or set, and the camera canbe made to perform a desired operation corresponding to the displayedicon mark.

In the following, the configuration of main parts of the electriccircuit accommodated in the camera body will be explained with referenceto FIG. 4. In FIG. 4, constituents identical to those shown in FIGS. 1to 3 are referred to with marks identical thereto.

In FIG. 4, as a controller for integrated control of operations of thisdigital camera, two pieces of microprocessors MPU1 and MPU2 areprovided. These processors perform the integrated control by executingan application program which has been prepared on the basis of apredetermined algorithm and formed into firmware.

The microprocessor MPU1 detects the operations of the above-mentionedvarious operation switches and buttons 12 to 18 and 32 to 36, andcontrols the operation of the image pickup mechanism including the imagepickup optical system 2 as well as the display operation of the liquidcrystal display section 30 or the like. Also, the microprocessor MPU1detects the operation of the zoom button 18 at the time of photographingmode, and drives, by way of a driving circuit 66, a zoom motor 68 so asto continuously move a zoom lens in the image pickup optical system 2along the optical axis direction. Also, it instructs the automatic focusdetector 4, which includes an automatic focus detecting unit 70, adriving circuit 72, and a focus motor 74, to perform distance-measuringand focusing processings. Further, it performs such a processing asdetection of whether the auxiliary memory MC is attached to or detachedfrom the camera.

In the photographing mode, the microprocessor MPU2 controls theoperation of a photoelectric converting mechanism for photoelectricallyconverting an object light image transmitted through the image pickupoptical system 2, so as to form predetermined image data. Also, itperforms so-called data processing such as storing of these image datainto the main memory MM or auxiliary memory MC or transferring andcopying the image data from the main memory MM to the auxiliary memoryMC in the copying mode. Further, it controls the program voltagesupplied to the main memory MM and auxiliary memory MC.

Here, the above-mentioned photoelectric converting mechanism comprises acolor CCD solid-state imaging device 76 for photoelectrically convertingthe object light image transmitted through the image pickup opticalsystem 2 into an image signal; a process circuit 78 which performs sucha processing as white balance adjustment with respect to the imagesignal output from the CCD solid-state imaging device 76; an A/Dconverter 80 which digitally converts the image signal output from theprocess circuit 78 into image data; and a CCD driving circuit 82 whichsynchronously controls these members according to instructions from themicroprocessor MPU2.

Connected to a bus B of the microprocessor MPU2 are the A/D converter80, a frame memory FM, the main memory MM, and a connector 84 forattaching the auxiliary memory MC thereto.

Here, the connector 84 is attached to the interior of the card slot 38(see FIG. 2). The main memory MM is a permanent memory fixedly attachedto the inside of the digital camera beforehand. Adopted as this memoryis a non-volatile semiconductor memory such as a flush memory which isrewritable by so-called program voltage. It has a storage capacity suchthat image data corresponding to a plurality of sheets of so-calledframe pictures can be stored therein. The memory card, which is theauxiliary memory MC, has a large storage capacity which can store imagedata corresponding to a number of sheets of so-called frame pictureswhich is greater the number of frame pictures which can be stored in themain memory MM.

In addition to so-called data bus and address bus and a control bus orthe like for memory resetting and the like, the bus B has a power linefor supplying the above-mentioned program voltage to the main memory MMand auxiliary memory MC. By way of this power line, the microprocessorMPU2 controls the supply of the program voltage to the main memory MMand auxiliary memory MC. Namely, a DC/DC converter 86 generates theabove-mentioned program voltage from the battery in the container 42 orthe external power source supplied by way of the connector 22, and themicroprocessor MPU2 controls a switching circuit 88, whereby the programvoltage is supplied to the main memory MM and auxiliary memory MC by wayof the power line.

At the time of photographing, the microprocessor MPU2 causes the imagedata corresponding to one frame picture output from the A/D converter 80to be temporarily stored into the frame memory FM and then, whilesubjecting thus temporarily stored image data to an image datacompressing processing with a ratio of compression corresponding to adesignated resolution, causes the image data to be stored into the mainmemory MM or auxiliary memory MC. Also, in the copying mode, themicroprocessor MPU2 performs transfer control in which the image data istransferred from the main memory MM to the auxiliary memory MC by way ofthe bus B.

Further, connected to the microprocessor MPU2 is a transmitter-receivercircuit 90 for serially transmitting the image data to an externalelectronic device connected to the serial port 20.

Thus, the microprocessors MPU1 and MPU2 share control functions andsynchronously operate so as to transfer various kinds of necessary datato each other.

In the following, main operations of this digital camera will beexplained with reference to FIGS. 5 to 10.

In the flow chart of FIG. 5, when an operator moves the slide cover 12and thereby turns on the main power source by way of the main switch,the microprocessors MPU1 and MPU2 initialize the whole camera system atstep S2. Subsequently, at step S4, the microprocessors MPU1 and MPU2make the liquid crystal display section 30 display the icon marks 46 to66, thereby indicating the operation mode which has been set and storedsince the last time the main power source was turned off aftercompletion of photographing as well as the current inner state of thecamera.

In such a state of display, when the auxiliary memory MC is not attachedto the camera, the microprocessor MPU2 investigates number n of imagedata already stored (i.e., the number of sheets already photographed) inthe main memory MM, divides the capacity of free area remaining in themain memory MM by a quantity of image data corresponding to one framepicture which is necessary when photographed with the currently setresolution, so as to determine number N of image data which can bestored (number of sheets which can be photographed), and then transferthese data n and N to the microprocessor MPU1. Then, as shown in FIG. 6,the microprocessor MPU1 displays, by means of the icon mark 60, thenumber n of the image data already stored in the main memory MM, whiledisplaying, by means of the icon mark 56, the number N of the image datawhich can be stored (number of sheets which can be photographed) in themain memory MM. Further, by not displaying the icon mark 64, it alsoindicates that the camera is in a mode for storing image data into themain memory MM.

By contrast, when the memory card MC, i.e., auxiliary memory, isattached to the camera, the microprocessor MPU2 investigates number m ofimage data already stored (i.e., the number of sheets alreadyphotographed) in the auxiliary memory MC, divides the capacity of freearea remaining in the auxiliary memory MC by a quantity of image datacorresponding to one frame picture which is necessary when photographedwith the currently set resolution, so as to determine number M of imagedata which can be stored (number of sheets which can be photographed),and then transfer these data m and M to the microprocessor MPU1. Then,as shown in FIG. 8, the microprocessor MPU1 displays, by means of theicon mark 60, the number m of the image data already stored in theauxiliary memory MC, while displaying, by means of the icon mark 56, thenumber M of the image data which can be stored (number of sheets whichcan be photographed) in the auxiliary memory MC. Further, by displayingthe icon mark 64, it also indicates that the camera is in a mode forstoring image data into the auxiliary memory MC.

Here, the microprocessor MPU1 electrically detects whether the auxiliarymemory MC is attached to or detached from the connector 84, and theninstructs the microprocessor MPU2 to perform the correspondingprocessing mentioned above.

Then, when the mode switch 32 is pushed, the microprocessor MPU1 detectsit (step S6), and the operation proceeds to a mode changing processing(step S8) for selecting and changing the operation mode of the camera.This operation for changing and selecting the mode is effected as theoperator appropriately manipulates the mode switch 32 and the selectswitch 34.

By contrast, when the select switch 34 is pushed without any selectingand changing of the operation mode being designated at step S6, themicroprocessor MPU1 detects it (step S10) and, simultaneously, instructsthe microprocessor MPU2 to perform a processing for a copying mode(steps S42 to S68).

When neither the mode switch 32 nor the select switch 34 is pushed, anormal photographing mode (steps S12 to S38) is taken.

Thus, as the operator arbitrarily manipulates the mode switch 32 and theselect switch 34, various operation modes can be selected, and the imagepickup mode or copying mode can be set.

In the photographing mode, the microprocessor MPU1 detects the pushingoperation of the zoom switch 18 at steps S12, S14, and S16, and performsso-called zoom-in and zoom-out operations respectively according to theshifting of the zoom switch 18 toward the telephoto contact (TSW) sideand the wide-angle contact (WSW) side.

Also, when the operator pushes down the shutter release button 16, themicroprocessor MPU1 detects it (step S18) and performs a photographingprocessing (step S20).

Namely, at step S20, the object image signal output from the color CCDsolid-state imaging device 76 is converted into digital image data bythe A/D converter 80, while thus obtained image data corresponding toone frame picture are temporarily stored in the frame memory FM.

Then, at step S22, the microprocessor MPU1 judges whether or not theauxiliary memory (memory card) MC is attached to the connector 84. Inthe case where the auxiliary memory MC is not attached thereto, theprocessing shifts to a storing mode (steps S24 to S30) for automaticallyrecording the image data into the main memory MM. In the case where theauxiliary memory MC is attached to the camera, the processing shifts toa recording mode (steps S32 to S38) for automatically and preemptivelyrecording the image data into the auxiliary memory MC.

In the above-mentioned case where the auxiliary memory MC is notattached to the camera, the microprocessor MPU2 investigates the storagecapacity of the free area in the main memory MM (step S24), writes apredetermined management data FDATA into a predetermined storage areafrom the start address (steps S26 and S28), and then causes the imagedata in the frame memory 78 to be stored into the free area subsequentto the management data, while subjecting the image data to a datacompressing processing corresponding to a designated resolution (stepS30). After the image data corresponding to one frame picture are thusstored, one shot of photographing is completed. During a period in whichthe main power source is not turned off at step S40, the processingsubsequent to step S4 is rep eated so as to enable the nextphotographing operation.

Here, as the above-mentioned management data FDATA, intrinsic data, suchas file name, for managing each image data in terms of file as well asdata representing the number of copying operations or the like used inthe copying mode which will be explained later are defined.

The processing of steps S24 to S30 is repeated each time thephotographing operation is effected, whereby image data F0 to F5 and soon re spectively corresponding to designated resolutions aresuccessively stored together with their management data FDATA asindicated by a memory map of the main memory MM shown in (a) of FIG. 10.Namely, at step S30, since the image data are compressed with a datacompression ratio corresponding to the resolution designated by theoperator, and then stored in the above-mentioned free area of the mainmemory MM, the capacity occupied by the image data corresponding to oneframe picture in the free area of the main memory MM is maximized in thesuperfine mode, becomes the secondarily largest in the fine mode, and isminimized in the normal mode.

Further, as the processing of step S4 is performed each time thephotographing operation is repeated, the displays of the number ofsheets photographed and the number of sheets which can be photographedin the main memory MM are changed each time one shot of photographing iscompleted. Accordingly, as shown in FIG. 7, the number of sheetsphotographed which is displayed by the icon mark 60 increases one by onefrom n+1 to n+j, while the number of sheets which can be photographed isdisplayed by the icon mark 56 as decreasing from N1 to Nj.

Here, each value of the numbers N1 to Nj of sheets which can bephotographed corresponds to the ratio of the capacity of the free areain the main memory MM to a designated resolution. Accordingly, even whenthe capacity of the free area is held constant, the values of thenumbers N1 to Nj of sheets which can be photographed become smaller asthe photographing operation is performed at a higher resolution (e.g.,in the superfine mode), whereas these values become greater as thephotographing operation is performed at a lower resolution (e.g., in thenormal mode).

Therefore, each time one shot of photographing is completed, theoperator can be provided with secure and clear information about thenumber of sheets which can be photographed in the main memory MM.

In the case where the auxiliary memory MC is attached to the camera, themicroprocessor MPU2 investigates the storage capacity of the free areain the auxiliary memory MC (step S32), writes a predetermined managementdata FDATA into a predetermined storage area from the start address(steps S34 and S36) in the free area of the auxiliary memory MC, andthen causes the image data in the frame memory 78 to be stored into thefree area subsequent to the management data, while subjecting the imagedata to a data compressing processing corresponding to a designatedresolution (step S38). After the image data corresponding to one framepicture are thus stored, one shot of photographing is completed. Duringa period in which the main power source is not turned off at step S40,the processing subsequent to step S4 is repeated so as to enable thenext photographing operation using the auxiliary memory MC.

The processing of steps S32 to S38 is repeated each time thephotographing operation is effected, whereby the image data F0 to F5 andso on respectively corresponding to designated resolutions aresuccessively stored together with their management data FDATA asindicated by the memory map shown in (a) of FIG. 10. Namely, at stepS38, since the image data are compressed with a data compression ratiocorresponding to the resolution designated by the operator, and thenstored in the above-mentioned free area of the auxiliary memory MC, thecapacity occupied by the image data corresponding to one frame picturein the free area of the auxiliary memory MC is maximized in thesuperfine mode, becomes the secondarily largest in the fine mode, and isminimized in the normal mode.

Further, as the processing of step S4 is performed each time thephotographing operation is repeated, the displays of the number ofsheets photographed and the number of sheets which can be photographedin the auxiliary memory MC are changed each time one shot ofphotographing is completed. Accordingly, as shown in FIG. 9, the numberof sheets photographed which is displayed by the icon mark 60 increasesone by one from m+1 to m+k, while the number of sheets which can bephotographed is displayed by the icon mark 56 as decreasing from M1 toMk.

Here, each value of the numbers M1 to Mk of sheets which can bephotographed corresponds to the ratio of the capacity of the free areain the auxiliary memory MC to a designated resolution. Accordingly, evenwhen the capacity of the free area is held constant, the values of thenumbers M1 to Mk of sheets which can be photographed become smaller asthe photographing operation is performed at a higher resolution (e.g.,in the superfine mode), whereas these values become greater as thephotographing operation is performed at a lower resolution (e.g., in thenormal mode).

Therefore, each time one shot of photographing is completed, theoperator can be provided with secure and clear information about thenumber of sheets which can be photographed in the auxiliary memory MC.

Thus, when the auxiliary memory MC is attached to the camera, image dataare automatically and preemptively stored not in the main memory MM butin the auxiliary memory MC which has a larger storage capacity.

Accordingly, though no particular difference exists in terms ofoperation for the operator between the case where image data are storedinto the main memory MM and the case where they are stored into theauxiliary memory MC, the auxiliary memory MC with a larger capacity isattached to the camera when photographing is to be effected with ahigher resolution or when a greater number of sheets are to bephotographed.

Also, when the photographing operation is performed while the auxiliarymemory MC is appropriately attached to or detached from the camera, theimage data storing modes for the main memory MM and auxiliary memory MCare automatically switched over therebetween at step S22 according towhether the auxiliary memory MC is attached to the camera or not.Accordingly, without any particular operation necessitated,photographing with the main memory MM alone and photographing with theauxiliary memory MC can be alternately effected.

In the following, the operation where the copying mode is selected atthe above-mentioned step S10 will be explained. Namely, when themicroprocessor MPU1 detects that the select switch 34 is pushed, at stepS42, it displays the icon mark 62 and, simultaneously, sends thisdetection information to the microprocessor MPU2, thereby starting thecopying mode.

First, at step S44, the microprocessor MPU2 investigates number α ofimage data already stored (number of sheets recorded) in the main memoryMM, investigates capacity AR of the free area remaining in the auxiliarymemory MC, and then estimates number β which can be transferred andcopied to the auxiliary memory MC (number of recordable sheets) at thecurrently set resolution. Here, since the image data photographed with avariety of resolutions are stored in the main memory MM, the remainingfree capacity AR in the auxiliary memory MC and these image data with avariety of resolutions may be compared with each other so as todetermine actual number β′ of image data which can be copied. In orderto shorten the processing time and so on, however, the number β of imagedata which can be transferred and copied to the auxiliary memory MC isestimated from the ratio of the currently set resolution to the freecapacity AR remaining in the auxiliary memory MC.

Next, at step S46, as shown in display example #1 in FIG. 11, themicroprocessor MPU1 makes the icon mark 56 display the number α of imagedata already stored in the main memory MM, while making the icon mark 60display the estimated number β which can be copied to the auxiliarymemory MC, and then waits till it is instructed to start copying.Accordingly, for example, when six pieces of image data F0 to F5 havealready been stored in the main memory MM as indicated by the memory mapin (a) of FIG. 10, the value α of the icon mark 56 becomes 6, whereasthe value β of the icon mark 60 becomes the above-mentioned estimatednumber.

Thus, since the values α and β are displayed before copying is actuallystarted, the operator can confirm the remaining capacity of theauxiliary memory MC or the like and, when this storage capacity isinsufficient, it is indicated, for example, that the auxiliary memory MCshould be replaced by another auxiliary memory MC' with a sufficientstorage capacity.

Next, when the mode switch 32 and the select switch 34 are pushedtogether so as to instruct the camera to start copying, themicroprocessors MPU1 and MPU2 detect it (step S48) and then cause theabove-mentioned values α and β to be stored into predetermined internalregisters (step S50). Subsequently, at step S52, as shown in displayexample #2 in FIG. 11, while number B of image data which can be copiedto the auxiliary memory MC is displayed by the icon mark 56, number A ofuncopied image data is displayed by the icon mark 60. Namely, the valueB is equivalent to or greater than the value β shown in display example#1, while the value A is equivalent to the value α.

Next, the microprocessor MPU2 confirms the start address of the imagedata in the main memory MM to be initially copied and the start addressof the free area in the auxiliary memory MC (step S54), and then themanagement data FDATA in the image data of the initial copying source isstored in the auxiliary memory MC as a new management data CDATA for thecopying destination (step S56). Here, to the new management data CDATA,data TIME representing the date and time of copying as well as flag dataFG representing the state of copying which will be explained later areadded.

Then, the microprocessor MPU2 causes the first image data to betransferred and copied in succession to the management data FDATA (stepsS58 and S60).

Here, the following operation should be noted in particular. At stepS58, simultaneously as copying of one piece of image data is started,the microprocessor MPU2 simultaneously writes a flag data FG (binary 01)indicating that the copying has been started and is in progress; then,after image data for one picture sheet have been completely transferredand copied, at step S60, writes a flag data FG (binary 11) indicatingthat one sheet has been completely copied; and further, while adding 1to the copied number data in the management data accompanying the imagedata in the main memory MM (copying source), re-stores the copied numberdata together with a data representing the date and time of copying.

Thus, the flag data FG indicative of the state during the copyingprocessing is stored. Accordingly, for example, when the auxiliarymemory MC is removed in the process of copying, the flag data FG=11indicative of the completion of copying is not stored while only thecopying start flag data FG=01 is left as being stored. Therefore, byinvestigating the contents of the flag data FG, the operator can judgewhether copying has been done securely or not.

Also, since so-called history information of the number of copying andthe date and time of copying is stored in the management data FDATA inthe image data of the copying source, this processing is effective, forexample, in preventing a third party from illegally performing a copyingoperation.

Next, at step S62, by subtracting 1 from the number A held in theabove-mentioned predetermined internal register, the microprocessor MPU2calculates number A-1 of uncopied image data in the main memory MM.Also, it reconfirms the free area capacity in the auxiliary memory MCagain and computes number BF1 of copiable sheets, which is then storedin the above-mentioned inner register. Then, at step S64, as shown indisplay example #3 in FIG. 11, the microprocessor MPU2 makes the iconmark 56 display the number BF1 of the copiable sheets and,simultaneously, makes the icon mark 60 display the number A-1 of theremaining uncopied image data.

Here, the capacity of the copied image data varies in response to theresolution set at the time of photographing, thereby occupying avariable capacity in the auxiliary memory MC in response to a differencein the resolution. Accordingly, the number BF1 of copiable sheetsdecreases as the resolution is higher.

Next, the microprocessor MPU2 judges whether the remaining free capacityin the auxiliary memory MC is sufficient for transferring and copyingthe next image data thereto (step S66). Namely, when the number ofcopiable sheets in the auxiliary memory MC becomes zero while thereremain image data to be copied, it is a state in which the next imagedata cannot securely be transferred and copied, whereby the operationshifts to the processing of step S72 which will be explained later. Bycontrast, when the number of copiable sheets is not zero, it is a statewhere the next image data can be securely transferred and copied,whereby the operation shifts to the processing of step S68.

Subsequently, at step S68, the microprocessor MPU2 confirms whether ornot there are remaining uncopied image data and, when it is judged thereare, repeats the processing subsequent to step S54 so as to transfer andcopy the remaining uncopied image data in a manner similar to thatmentioned above. After the whole image data is transferred and copied,the copying mode is terminated (step S70).

Thus, each time the individual image data is transferred and copied, thevalues of the icon marks 56 and 60 are changed as indicated by displayexamples #2 to #5 in FIG. 11. After the whole image data is transferredand copied, as indicated by display example #5 in this drawing, thevalue of the icon mark 60 becomes zero, indicating that the whole imagedata has been copied.

According to such a processing of copying mode, for example, when sixpieces of image data F0 to F5 have already been stored in the mainmemory MM as indicated by the memory map in (a) of FIG. 10, after thecopying processing, all the image data F0 to F5 are copied into theauxiliary memory MC in the same order with their respective managementdata added thereto as indicated by a memory map of the auxiliary memoryMC shown in (b) of FIG. 10.

Thus, by simply seeing that the value of the icon mark 60 has becomezero, the operator can easily judge that the whole image data hascompletely been copied.

Here, in the case where the capacity of the storable area in theauxiliary memory MC has become insufficient before the whole image datain the main memory MM is completely transferred and copied, unlikedisplay example #5 in FIG. 11, the value (copiable number) in the iconmark 56 initially becomes zero, while the value of the icon mark 60indicates the number (≠0) of uncopied image data.

At step S66, such a state where the free capacity in the auxiliarymemory MC is insufficient while there remain uncopied image data (statewhere the next transferring and copying operation cannot be effected) isdetected, and the operation shifts to the processing of step S72 so asto respond to this state.

First, the microprocessor MPU2 causes data such as the number ofuncopied image data remaining in the main memory MM (number of remainingdata to be copied) and the start address of the uncopied image data toevacuate into a predetermined inner register (step S72) and, with thecurrent auxiliary memory (memory card) MC detached therefrom, waits tillanother auxiliary memory (memory card) MC is attached thereto (stepS74). Then, when the microprocessor MPU1 detects attachment of anotherauxiliary memory (memory card) MC (step S74), the microprocessor MPU2revives thus evacuated data (step S74) and then investigates thecapacity AR of the free area in the auxiliary memory MC newly attached,thereby estimating the number β of image data which can be transferredand copied to the auxiliary memory MC (number of recordable sheets) atthe currently set resolution (step S78).

Then, as the operation continues to the processing subsequent to theabove-mentioned step S46, the remaining image data in the main memory MMare transferred and copied to the new auxiliary memory MC.

Thus, even when the storage capacity of the auxiliary memory MC becomesinsufficient during copying, the operator can view such a situation withthe icon marks 56 and 60, and further can continue copying to a new(another) auxiliary memory MC.

Here, even after such a copying processing is completed, the image datain the main memory MM are held as they are unless the erase switch 36 isoperated.

After the copying mode is completed, the processing from step S4 isstarted again, whereby the above-mentioned setting of operation mode aswell as setting of photographing mode and copying mode, again, can beeffected. Also, when the auxiliary memory MC used for copying is notdetached from the camera and has a sufficient storage capacity, theabove-mentioned photographing mode (steps S32 to S38) with the auxiliarymemory MC is taken; whereas the above-mentioned photographing mode(steps S24 to S30) with the main memory MM is taken when the auxiliarymemory MC used for copying is detached therefrom.

As explained in the foregoing, this embodiment has a copying mode inwhich image data stored in the main memory accommodated in the cameracan be copied, and sequentially displays the number of image data in themain memory, i.e., copying source, and the number of image data whichcan be copied to the auxiliary memory MC, i.e., copying destination.Accordingly, the operator can be provided with information about thestate of copying and the like, whereby a digital camera with anexcellent operability can be provided.

Also, while predetermined management data are added to individual imagedata stored in the main memory MM or auxiliary memory MC in the normalphotographing mode, the management data in the main memory MM are copiedin conjunction with the individual image data to be copied to theauxiliary memory MC. Accordingly, this embodiment yields excellenteffects in that the identity of the copied image data can be improved,while so-called data management can be facilitated.

Further, in the copying mode, since the state of individual image databeing transferred and copied is managed by writing of the predeterminedflag data FG, it can be securely judged whether the individual imagedata have been normally copied or not.

Also, this digital camera is provided with an abnormality monitoringmeans which prevents the main memory MM, the auxiliary memory MC, andthe bus B from malfunctioning or being damaged not only at the time ofthe above-mentioned copying mode but also when the auxiliary memory MCis suddenly attached to or detached from the camera during when variousdata are being transferred by way of the bus B.

This abnormality monitoring means is realized by the microprocessorsMPU1 and MPU2 in FIG. 4 as they execute an abnormality monitoringprogram which has been prepared on the basis of a predeterminedalgorithm indicated by a flow chart of FIG. 12 and formed into firmware.

Also, when such an abnormal state is generated, this abnormalitymonitoring program is preemptively executed independently from theprocessing operation indicated in the flow chart of FIG. 5.

With reference to FIG. 12, the principle and operation of theabnormality monitoring process will be explained. At step S100, themicroprocessor MPU1 detects and monitors whether the auxiliary memory MCis attached to or detached from the camera and the timing of theattaching or detaching operation.

Then, when the microprocessor MPU1 judges that there has been anattaching or detaching operation of the auxiliary memory MC (step S102),it is investigated whether the bus B is in an active state or not (stepS104). Namely, when the bus B is in so-called in-use state, such as thecase where image data are being transmitted to the frame memory 72, themain memory MM, or the auxiliary memory MC by way of the bus B at thetime of image pickup mode, the case where image data are beingtransmitted from the main memory MM to the auxiliary memory MC in thecopying mode, and the case where supply of the above-mentioned programpower source is being controlled, it is judged that the bus active stateis established.

Then, when the microprocessor MPU1 judges that the bus is in the activestate, it supplies a reset signal RESET to the microprocessor MPU2,thereby making the microprocessor MPU2 stop the foregoing processingoperation, while forcibly making the microprocessor MPU2 perform a reset(initializing) processing (step S106). Accordingly, the processingsubsequent to step S2 shown in FIG. 5 is restarted.

By contrast, when it is judged that the bus in not in the active state,from step S104, the processing of steps S108 to S114 is executed.Namely, when the auxiliary memory MC is attached to or detached from thecamera when the bus B is not in the active state, without the forciblereset processing at step S106 being performed, the microprocessors MPU1and MPU2 perform a known interrupt processing at step S108, therebyholding, in a predetermined shelter register, various kinds of dataindicative of the inner state of the camera.

Then, at steps S110 and S112, when the microprocessor MPU1 judges thatthe attachment or detachment of the auxiliary memory MC has beencompleted, i.e., that the auxiliary memory MC is in a state where it iscontinuously detached from or attached to the camera, the processingshifts to step S114, at which a known interrupt return processing isperformed, whereby the control operation is started from the statebefore the auxiliary memory MC is attached or detached.

Namely, even in the case where attachment or detachment of the auxiliarymemory MC occurs, when the bus B is not in the active state, there is noproblem such as noise being superposed onto image data or the like.Also, since no high-speed data transmission is effected, there is amargin in terms of time. Accordingly, a normal interrupt processing iseffected.

When a forcible reset processing is performed when attachment ordetachment of the auxiliary memory MC has occurred where the bus B is inthe active state, the following effects are attained.

When attachment or detachment of the auxiliary memory MC occurs wherethe bus B is in the active state, there may be problems such as loweringof reliability due to noises superposed onto image data and the likewhich are being transmitted. Since initialization is made by resetting,these problems can be eliminated.

When such problems are to be eliminated by so-called interruptprocessing, the state before the interrupt processing is regained aftervarious data are evacuated, thereby making it impossible to realize afast eliminating processing. By contrast, as the reset processing isperformed in this embodiment, a fast eliminating processing can berealized.

Here, though the data on the bus B disappear upon such a forcible resetprocessing, the image data once stored in the main memory MM orauxiliary memory MC made of a non-volatile semiconductor memory do notdisappear. Accordingly, so-called accidental information breakdown doesnot occur.

Also, when attachment or detachment of the auxiliary memory MC occurswhere the bus B is in the active state, the program sequence (writingsequence) of the main memory MM and auxiliary memory MC can be forciblyand easily initialized. In particular, it becomes unnecessary for thepower line or the like in the bus B, which is used for supplying theprogram voltage or the like to the main memory MM and auxiliary memoryMC, to be switched over in order to perform an eliminating processing.Accordingly, while the system for switching the bus can be omitted, itbecomes unnecessary for the disorder of the bus or the like to be takeninto consideration.

Further, as the above-mentioned reset processing and the normalprocessing are selectively executed, effects such as those explained inthe following can be obtained.

In a typical system adopting a microprocessor, in order to connectconstituents such as connectors and I/O ports or external devices to abus, these constituents are always connected to the bus by way of an I/Obuffer circuit (bidirectional tristate buffer circuit), while unused I/Obuffers are controlled so as to be in their off state (high-impedancestate), whereby only necessary constituents are substantially connectedto the bus so as to prevent intrusion of external noise and interferencebeforehand.

In the digital camera of the present invention, however, the number ofparts should be reduced as much as possible in order to attain a smallersize and lighter weight as well as a lower power consumption.Accordingly, great effects can be attained even when the I/O buffer,which has been considered essential in general, is omitted.

Therefore, in this embodiment, without the above-mentioned I/O bufferbeing provided, the microprocessor MPU2, the frame memory FM, and themain memory MM as well as the A/D converter 80 and the connector 84 aredirectly connected to the bus B.

When the auxiliary memory MC is attached to or detached from theconnector 84, a certain fluctuation is clearly rendered to the bus B.When the bus B is not in the active state, the normal interruptprocessing is performed so as to cope with this situation, since noabnormality is generated in the camera system. When the bus B is in theactive state, it becomes an obvious cause for superposing noise onto theimage data being transmitted or the like. Accordingly, the resetprocessing is forcibly effected.

As a result, while generation of abnormality such as malfunctioning ofthe camera can be skillfully eliminated, the number of parts such as theI/O buffer and the bus switching system, at least, can be greatlyreduced, whereby the camera can attain a small size and light weight aswell as a low power consumption.

From the invention thus described, it will be obvious that the inventionmay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedfor inclusion within the scope of the following claims.

The basic Japanese Application No. 228114/1995 filed on Sep. 5, 1995 ishereby incorporated by reference.

What is claimed is:
 1. A method for digital photography of an object toobtain an image signal, said method comprising the steps of: capturingan image of said object to obtain said image signal; converting saidimage signal into digital image data; storing said image data in a mainmemory connected to a data bus having a connector suitable for attachingand detaching a detachable auxiliary memory to said data bus; if saidauxiliary memory is attached to said connector, preemptively causingsaid image data to be stored into said auxiliary memory; detecting ifsaid auxiliary memory is detached from said connector during transfer ofsaid image data to or from said main memory and forcibly initializingall elements of said digital camera; said initializing all elementscomprising the steps of: determining if said data bus is active or not,if said data bus active having a microprocessor supply a reset signal,if said data bus is not active, said microprocessor will store saiddigital image data in a predetermined shelter register.